We investigate what it means for a (Hausdorff, second-countable) topological group to be computable. We compare several potential definitions based on classical notions in the literature. We relate these notions with the well-established definitions of effective presentability for discrete and profinite groups, and compare our results with similar results in computable topology.

In this paper I shall venture into an area with which I am not very familiar and in which I feel far from confident; namely into phenomenology. My main motive is not to get away from standard, boring, methodological questions like those of induction and demarcation; but the conviction that a phenomenological account of the empirical basis forms a necessary complement to Popper's falsificationism. According to the latter, a scientific theory is a synthetic and universal, hence unverifiable proposition. In fact, (...) in order to be technologically useful, a scientific hypothesis must refer to future states-of-affairs; it ought therefore to remain unverified. But in order to be empirical, a theory must bear some kind of relation to factual statements. According to Popper, such a relation can only be one of potential conflict. Thus a theory T will be termed scientific if and only if T is logically incompatible with a so-called basic statement b, where b is both empirically verifiable and empirically falsifiable. In other words: T is scientific if it entails ¬b; where b, hence also ¬b, is an empirically decidable proposition. (shrink)

We give a systematic technical exposition of the foundations of the theory of computably compact metric spaces. We discover several new characterizations of computable compactness and apply these characterizations to prove new results in computable analysis and effective topology. We also apply the technique of computable compactness to give new and less combinatorially involved proofs of known results from the literature. Some of these results do not have computable compactness or compact spaces in their statements, and thus these applications are (...) not necessarily direct or expected. (shrink)

How far can we construct a framework within which to compare different traditions of philosophy and science across civilizations? The first problem lies with the terms “philosophy” and “science” themselves, for they carry particular associations in Western thought, some of which contribute to the mistaken view that they are uniquely Western activities. This brief article refutes that view, examining how we can compare the philosophical and scientific achievements of different cultures, and further challenging the sharp positivist dichotomy between “science” and (...) “philosophy” that stems from equating the former with facts, the latter with values. (shrink)

Free radicals are generally perceived as highly reactive species which are harmful to biological systems. There are, however, a number of enzymes that use carbon‐based radicals to catalyse a variety of important and unusual reactions. The most prominent example is ribonucleotide reductase, an enzyme which is crucial for the synthesis of DNA. In general, radicals are used to remove hydrogen from unreactive positions in the substrate, and in this way the substrate is activated to undergo chemical transformations that would otherwise (...) be difficult to achieve. Several different mechanisms have evolved which allow enzymes to generate and maintain radicals in increasingly aerobic enviroments. An unexpected finding is the existance of stable protein‐based radicals, residing on a variety of amino‐acid side chains, which serve to link the radical‐generating and catalytic sites and to store the radical between turnovers. (shrink)

We solve a problem posed by Goncharov and Knight 639–681, 757]). More specifically, we produce an effective Friedberg enumeration of computable equivalence structures, up to isomorphism. We also prove that there exists an effective Friedberg enumeration of all isomorphism types of infinite computable equivalence structures.

Despite the periodic table having been discovered by chemists half a century before the discovery of electronic structure, modern designs are invariably based on physicists’ definition of periods. This table is a chemists’ table, reverting to the phenomenal periods that led to the table’s discovery. In doing so, the position of hydrogen is clarified.

Coping with a relative with a learning disability could be a stressful experience for family members. The present study is aimed at exploring the coping strategies adopted by families in trying to make meaning of their situation. A qualitative study design using focus group discussions was adopted. Ten FGD sessions were held with family members of persons with a learning disability. Findings revealed patterns of family coping to include problem-focused, emotion-focused, and spiritual/religious-focused. Also, coping responses to a learning disability varied (...) based on the level of information available to families about the condition of their relative. In some cases, interspousal relationship was strained due to stress. It was recommended that families of persons with a learning disability need social support and professional help from social workers to facilitate the adoption of more positive-oriented coping strategies by family members. (shrink)

Bundel bijdragen over de Nederlandse filosoof (1632-1677).

The question of the essence of contemporary socialist artistic culture is being acutely posed today, in the period of renewal of the whole life of Soviet society. To what extent does the method of socialist realism, which has become established in our theory and practice, correspond to the processes taking place within art? Is its method adequate for an all-round reflection and analysis of the entire diversity and uniqueness of today's society? After all, the method of socialist realism presumes a (...) truthful, historically concrete depiction of reality in its revolutionary development, i.e., it orients the artist toward reflecting that reality only in "forms of life" and requires him to represent only progressive processes. (shrink)